Hidden Maryland: NASA Goddard clean room

— Once you've passed through a vestibule, an air shower, a changing room and three more doors separating the grime of life from the "clean room" where NASA is building the James Webb Space Telescope, a gust of 72-degree filtered air greets your face.

That's the only exposed skin allowed inside.

To prepare for the room, shoe-covering booties and a hair net go on first. Step out of the air shower onto a sticky pad (known to pull a shoe clean off) to remove any excess dirt underfoot. Don a four-piece head-to-toe jumpsuit, and don't forget the gloves — taped on around the wrists — and you're ready to go inside.

It's all for the sake of science. The telescope being constructed in the clean room is slated to career through Earth's atmosphere in 2018 en route to its home at what is known as the second Lagrange Point, nearly a million miles away. The controlled environment is key for preserving the integrity of the equipment.

That's because the stakes are as high as the possible rewards. The $8 billion telescope is one of NASA's top three priorities, the other two being new vehicles for space travel and exploration. It has been pitched since 1996 as a successor to the Hubble Space Telescope, but with the ability to give the farthest glimpses ever into the universe, just 100 million to 250 million years after the Big Bang.

"The same books that Hubble rewrote over the years, we're going to rewrite again," said Bill Ochs, the telescope's project manager at the NASA Goddard Space Flight Center, where key components are under construction inside the clean room. "Just like with Hubble, you're basically looking back in time. We'll be able to look at formation of the earliest stars and the first galaxies in the universe."

The clean room at Goddard, roughly a 100-foot cube, is where those eyes are being built, with collaboration from the Canadian and European space agencies and companies including Northrop Grumman Corp. Parts of the telescope have already criss-crossed the country, with remaining stops at the NASA Johnson Space Center in Houston and a Northrop facility in southern California before launch.

Recent work has focused on two of the telescope's four scientific instruments. The Mid-Infrared Instrument, or MIRI, is part camera, part spectrograph that will see in wavelengths longer than human eyes can to spot distant galaxies, newly forming stars and faintly visible comets. It will be responsible for capturing the next heavenly images that made Hubble so renowned.

The Fine Guidance Sensor, or FGS in NASA parlance, will guide the telescope's gaze using a built-in map of the stars to locate targets as much as 600 million years older than those Hubble can see.

For now, they look like the insides of massive television sets — the old cathode ray tube kind. But eventually, they will form the brains behind a three-story honeycomb-like array of 18 molded beryllium mirrors, coated in gold. Together they will sit atop a vast sun shield — about the size of a Boeing 737 airplane and made of six layers of a material similar to a Mylar balloon.

Until then, the cleanliness of the environment is paramount to ensuring those revolutionary images can be captured. The concern is not just degradation from dirt and dust, but also gases released by anything from cologne or makeup to silicone and some rubbers that can implant into space-bound equipment and compromise their function.

Among the room's rules, outlined in a 37-page contamination control training guide that must be read by anyone who enters: No "regular" paper allowed — only special clean room paper that has been coated with polymers to prevent fibers from spreading. No tearing of plastic bags — cut with scissors. No food or drinks.

Air is circulated in at a speed of 100 feet per minute, through a wall of filters that strain out anything larger than 0.3 millionths of a meter, to a perforated wall on the opposite side of the room. From there the air is circulated to a system above the room that also pumps in filtered fresh air. It all keeps air pressure inside the room slightly higher than the outside — creating the breeze when you enter.

"Think about your house. The dust piles up week after week," said Jason Hylan, lead mechanical engineer for the component under construction at Goddard. "We can't afford to have any of that pile up on this stuff."

For project engineers, it means spending as much as 10 or 12 hours a day suited up inside the clean room, often involved in tasks that require constant focus for hours at a time. Plus, something as quick as a bathroom break means removing anti-contamination suits and then going through the process all over again.

"It's annoying to do, but it's so super-important," said Theo Hadjimichael, an optical engineer.

NASA Goddard scientists who work on telescope components day in and day out, and often nights and weekends, say they are mindful of the importance of the work.

"The scientific community has been awaiting the James Webb Space Telescope for a long time," mechanical engineer Acey Herrera said on a recent morning on his way out of the clean room for lunch. "To be part of that is exciting, but it also carries a little bit of a burden."

The telescope poses engineering challenges tougher than your average brainteaser.

First, there's getting it into space. The telescope is no easy fit inside a rocket. It will be folded — "like origami", says NASA spokeswoman Lynn Chandler — inside the cone of a rocket at a launch site in the South American country of French Guiana. To get to that point, the telescope will travel by barge from Southern California through the Panama Canal — it's too large for anything else.

That's not to mention the engineering challenges once the telescope reaches its final destination. Unfolding, booting up and calibrating the telescope is a six-month process. Once it begins operating, it requires a design that keeps the instruments at temperatures around 30 degrees Kelvin — 400 degrees below zero in Fahrenheit — while nearby electronics that run and power the instruments maintain room temperature.

Because Hubble orbits the Earth a manageable 350 miles away, scientists have been able to troubleshoot major issues, with half a dozen servicing missions over the years. But no crew will ever lay eyes on the Webb telescope after it launches into space, settling 930,000 miles away, applying extra pressure to engineers to avoid mistakes.

Failure would mean "the progress of astronomy could be set back by a generation," according to a 2010 article in the scientific journal Nature that dubbed Webb "The telescope that ate astronomy."

Ochs acknowledges the complexity.

"Everything with the James Webb Space Telescope is a challenge, from how you ship it, to how you build it, to how you test it, to how you fly it in orbit," he said. "It does have some things that can keep you up at night."

Hidden Maryland is an occasional series taking readers to places that are normally off limits to most Marylanders. Have a suggestion for a next location? Tell us about it at baltimoresun.com/hiddenthoughts

NASA Goddard Clean Room

Where: NASA Goddard Space Flight Center in Greenbelt

You never would've guessed that: Any object that enters the clean room – whether a tool, forklift or pen – must go through an intense cleaning process that uses high-grade alcohol and, in some cases, acetone.